Means for converting zinc powder into fluid zinc



Nov. 23,1926. fl 1,608,358

E. S. BERGLUND MEANS FOR CONVERTING ZINC POWDER INTO FLUID ZINC v FiledF9!)- 2, 1922 Z SheetS-Sheet 1 I l I "a N g k \lTTw 611202 lzalicl 'ybwwNov. 23 1 26. 1,608,358

E. s. BE RGLUND MEANS FORCONVERTING ZINC POWDER INTO FLUID ZINC FiledFeb. 2, 1922 2 Sheets-Sheet 2 zai'dz l bull/(L,

Patented Nov. 23, 1926.

UNITED STATES PATENT OFF-ICE."

EDWAR SALOMON BERGLUND, or DJURSHOLM, SWEDEN.

MEANS FOR CONVERTING ZINC PDWIDER INTO FLUID ZINC.

Application filed February 2', 1922, Serial No. 533,701. and in SwedenFebruary 22, 1921.

l Vhen extracting zinc and lead, from their ores especiallyaccording toelectro-thermie methods, fluid metal is obtained in the condenser, asknown, from the metal gases escaping from the reduction furnace,together with a metallic powder, the so-called poussiere, which must besubjected to a treatment in one manner or another in order to obtainfluid metal therefrom. No method of operation is available at presentwhereby the generation of powder is wholly obviated in the process.

For treating the powder many different methods and devices have beenproposed. Among them there are devices, by means of which the powder issubjected to a mechanical treatment within the condenser, while stillwarm. Said treatment has been carried out accordingto hitherto proposedmethods either by providing the condenser-with-a' member, Z by themovement of I which the powder has been turned over or shaken, or atreatment has been carried out by means of apparatus, placed within ,thefurnace chamber. In apparatus of this latter kind screws or rolls or avertical shaft provided with vanes, have been employed. Said devices,however, in fact have only exerted a pressure on the metal powder,without agitating the same, which pressure has proved to be insufficientin practice for effectively converting the powder into metal, as forthis purpose alsothe powder must be stirred and rubbed. The apparatuswith. the vertical shaft carrying vanes is affected with theinconvenience, that the stirring is very ineffective, mainly resultingin imparting a rotary motion to the powder, and that the bearing of theshaft soon becomes obstructed by metal condensed from the gases, so thatthe shaft cannot be rotated. The present invention relates to a'deviceby means of which the mixture of powder and fluid metal, formed in thecondenser during the condensation, may be violently agitated within thecondenser, being subjected partly to repeated lifting operations, sothat the several particles may be effectively rubbed together.

On the accompanying drawing Fig. 1 is a vertical section of the lowerpart of a condenser for zinc-lead gases showing the stirring apparatusaccording to the present invention. Fig. 2 is a vertical section of thecondenser at flight angles to Fig. 1. Figs.

3-8 show several modified forms of the stir.-. ring members.

For obtaining the resultabove referred to the-apparatus 1, by means'ofwhich the stirring operation is performed, are secured to horizontalshafts 2, which penetrate the condenser wall 3 at a point in the lowerpart of the condenser adjacent to the bottom of the same, so that thepowder always covers the point, where the shafts 2 penetrate thecondenser wall 3. By this means the metal vapours are prevented frompenetrating the bearings, and from obstructing the same. The stirringmembers 1 consist of propeller ,shaped apparatus of fire proof materialor other material resisting the influence of heat and fluid Zinc or leador zinc-lead alloy. The mixture of fluid metal and powder falling downfrom the upper part of the condenser, is immediately treated by thestirring members 1, and'the generation of metal from the powder ismoreover promoted thereby, as the metal, formed in the open condenserchamber is not separated from the powder, but partakes in the stirringoperation established by the stirring members. The several vanes orspokes of the propeller shapedstirringmembers may be unequal as to theirform, so that the successive vanes or spokes do not follow the sametrack, whereby the stirring operation is promoted.

Fig. 3 shows the form of the vane 4 which is shown in Fig. 4 in sideview, whereas Fig. '5 shows the form of the vane 5 in plan. The vane 42in Fig. 4 may also have the form shown in full lines in side view inFig. 6, whereas the vane 5 has the form shown in dotted lines in Fig. 6.Figs. 7 and 8 show in side view and end view one form of a stirringmember, by means of which an alternative displacement of the powdersideways is established simultaneously with the stirring operation owingto the rotation of the vanes. A multitude of other forms than shown onthe drawing may be used. The members receive their motion from a shaftnot shown outside of the condenser. By varying the direction of motion,speed, size and form of the several stirring members, the greatestpossible effect may beobtained. The shaft 2 is journalled outside thewall 3 of the condenser, through which the shafts 2 passes, as shown onthe drawing. This, however, is not essential. Manholes may be made inthe wall 6 opposite the stirrersthrough which the stirring members maybe accessible or may be exchanged.

The fluid metalformed by the condensation and the treatment of thepowder, is

' gathered on the bottom of the condenser,

from which it is tapped. As owing to several clrcumstances in extractingzinc and lead from ore in the elec-- ping the metal in shorter or longerintervals the powder can be subjectedito the treatment during a shorteror longer time, in view of the fact that the powder, floating on thesurface of the metal bath, is raised towards the stirring members andcan be kept there for any desired time. I

Having now described my invention, what I claim new and desire to secureby Letters Patent is 2-- 1. In a device for extracting zinc and lead, acondenser, and a lurality of stirring members, consisting of rotaryvanes, placed in spaced relation to one another in the lower part of thecondenser, receivingvthe metal powder, formed during the condensation,to violently agitate'said powder.

- 2. In a device for extracting zinc and lead,

a condenser, and a plurality of stirring members, consisting of rotaryvanes of unequal form, placed in spaced relation to one another onhorizontal shafts,embcdded in the metal powder formed duringithecondensa-- tion, to violently agitate said powder.

ded in the metalrpowder. gathered at the bot tom of the condenser, toviolently agitate said powder. V I

4. In a device for extracting zinc and lead, a condenser, and aplurality of groups of stirring members, each group consisting of aplurality of rotary vanes, placed ,in spaced relation to one another ona horizontal shaft, embedded in the metal powder gathered at the bottomof the condenser, to violently agitate said powder.

5. In a device for extracting zinc and lead, a condenser, and aplurality of rotary vanes, placed in spaced relation to one another inthe lower part of condenser, and

formed so as to establish an alternating displacement in opposite sidedirections of the metal powder, formed in the condenser, to violentlyagitate said powder. 7

In testimony whereof I have signed my name to this specification.

EDWARD SALOMONBERGLUND.

